253 research outputs found
LOPINGIAN (LATE PERMIAN) BRACHIOPOD FAUNAS FROM THE QUBUERGA FORMATION AT TULONG AND KUJIANLA IN THE MT. EVEREST AREA OF SOUTHERN TIBET, CHINA
Permian strata containing abundant brachiopods are well developed in the Himalaya Tethys Zone. However, relatively few has been systematically described due to the difficult working condition for collecting. In this paper, we describe the brachiopods from the Qubuerga Formation at the Tulong and Kujianla sections in southern Tibet. The brachiopod faunas consist of 15 species belonging to 11 genera. Among the identified 15 species, Retimarginfera xizangensis, Costiferina indica, Fusispirifer semiplicatus, Spiriferella sinica, Biplatyconcha grandis and Neospirifer (Quadrospina) tibetensis are very common in the equivalents of the Himalaya Tethys Zone including the Selong Group at the Selong Xishan and Qubu sections in southern Tibet, the Senja Formation in northwest Nepal, the Zewan Formation in Kashmir, and the upper part of the Wargal Formation and the Chhidru Formation in the Salt Range, Pakistan. They are all comparable and can be assigned to the Wuchiapingian- early Changhsingian. Since the brachiopods from the Qubuerga Formation at Tulong and Kujianla are all composed of typical Gondwanan, bipolar or cosmopolitan elements, it is conclusive that the Himalaya Tethys Zone in the northern margin of the Indian Plate was still situated at southern high-latitudes under cold palaeoclimatic conditions during most of the Lopingian. The faunal succession at Tulong also recorded a rapid warming at the very end of the Changhsingian in view of the fact that the typical cold-water Lopingian brachiopod, gastropod and bivalve faunas were dramatically replaced by extremely abundant conodonts Clarkina in the basal part of the dolostone unit of the Tulong Formation. This end-Changhsingian warming is comparable with that recorded throughout the Permian-Triassic boundary interval at Selong, Qubu in southern Tibet, the Salt Range, Pakistan and the sections in Kashmir as well as South China
Physics perspectives of heavy-ion collisions at very high energy
Heavy-ion collisions at very high colliding energies are expected to produce
a quark-gluon plasma (QGP) at the highest temperature obtainable in a
laboratory setting. Experimental studies of these reactions can provide an
unprecedented range of information on properties of the QGP at high
temperatures. We report theoretical investigations of the physics perspectives
of heavy-ion collisions at a future high-energy collider. These include initial
parton production, collective expansion of the dense medium, jet quenching,
heavy-quark transport, dissociation and regeneration of quarkonia, photon and
dilepton production. We illustrate the potential of future experimental studies
of the initial particle production and formation of QGP at the highest
temperature to provide constraints on properties of strongly interaction
matter.Comment: 35 pages in Latex, 29 figure
Climate Variability and Hemorrhagic Fever with Renal Syndrome Transmission in Northeastern China
Background: The transmission of hemorrhagic fever with renal syndrome (HFRS) is influenced by climatic variables. However, few studies have examined the quantitative relationship between climate variation and HFRS transmission. ---------- Objective: We examined the potential impact of climate variability on HFRS transmission and developed climate-based forecasting models for HFRS in northeastern China. ---------- Methods: We obtained data on monthly counts of reported HFRS cases in Elunchun and Molidawahaner counties for 1997–2007 from the Inner Mongolia Center for Disease Control and Prevention and climate data from the Chinese Bureau of Meteorology. Cross-correlations assessed crude associations between climate variables, including rainfall, land surface temperature (LST), relative humidity (RH), and the multivariate El Niño Southern Oscillation (ENSO) index (MEI) and monthly HFRS cases over a range of lags. We used time-series Poisson regression models to examine the independent contribution of climatic variables to HFRS transmission. ----------- Results: Cross-correlation analyses showed that rainfall, LST, RH, and MEI were significantly associated with monthly HFRS cases with lags of 3–5 months in both study areas. The results of Poisson regression indicated that after controlling for the autocorrelation, seasonality, and long-term trend, rainfall, LST, RH, and MEI with lags of 3–5 months were associated with HFRS in both study areas. The final model had good accuracy in forecasting the occurrence of HFRS. ---------- Conclusions: Climate variability plays a significant role in HFRS transmission in northeastern China. The model developed in this study has implications for HFRS control and prevention
3-(3-Pyridylmethylidene)-2-indolinone Reduces the Severity of Colonic Injury in a Murine Model of Experimental Colitis
Nrf2 is the key transcription factor regulating the antioxidant response which is crucial for cytoprotection against extracellular stresses. Numerous in vivo studies indicate that Nrf2 plays a protective role in anti-inflammatory response. 3-(3-Pyridylmethylidene)-2-indolinone (PMID) is a synthesized derivative of 2-indolinone compounds. Our previous study suggested that PMID induces the activation of Nrf2/ARE pathway, then protecting against oxidative stress-mediated cell death. However, little is known regarding the anti-inflammatory properties of PMID in severe inflammatory phenotypes. In the present study we determined if PMID treatment protects mice from dextran sodium sulphate- (DSS-) induced colitis. The result suggests that treatment with PMID prior to colitis induction significantly reduced body weight loss, shortened colon length, and decreased disease activity index compared to control mice. Histopathological analysis of the colon revealed attenuated inflammation in PMID pretreated animals. The levels of inflammatory markers in colon tissue and serum were reduced associated with inhibition of NF-κB activation. The expression levels of Nrf2-dependent genes such as HO-1, NQO1, and Nrf2 were increased in PMID pretreated mice. However, PMID pretreatment did not prevent DSS-induced colitis in Nrf2 knockout mice. These data indicate that PMID pretreatment in mice confers protection against DSS-induced colitis in Nrf2-dependent manner, suggesting a potential role of PMID in anti-inflammatory response
Inhibition action and adsorption behavior of environment-friendly inhibitor poly-aspartate on copper
The inhibition action and adsorption behavior of an environment-friendly inhibitor poly-aspartate (PASP) on copper in aqueous NaCl (0.02%) solution were investigated by means of electrochemical techniques. The results indicated that the best inhibition efficiency of PASP was 78.3% with the concentration of 15 mg center dot L-1 at 20 degrees C. The adsorption of PASP prevented Cu from being corroded and PASP was an anodic inhibitor. The inhibition efficiency of PASP decreased with the increase in solution temperature, it decreased to 40.4% at 50 degrees C. The adsorption behavior of PASP followed Langmuir isotherm, it was spontaneous and exothermic, and belonged to chemical adsorption
Photoelectrochemical study of influence factors on corrosion resistance of cupronickel B30 in simulated water
Influence factors on semiconduction properties of oxide films on a cupronickel electrode in the simulated water was studied by cyclic voltammetry and photocurrent response method. The cupronickel electrode showed p-type photoresponse, which came from CU2O layer on its surface. The photoresponse changed to n-type in the simulated water. The transition from p-type to n-type might be related to the doping of Cl- and SO42- anions into CU2O film. It did not show n-type photoresponse when the cupronickel electrode was immersed in the simulated water containing some sulfide. It was shown that the degree of corrosion increased with the concentration of these anions and temperature. In addition, as the pH increased between 7 and 9, the corrosion resistance of B30 was enhanced, while it lowered as the pH was beyond 9
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Morphological segmentation analysis and texture-based support vector machines classification on mice liver fibrosis microscopic images
Background To reduce the intensity of the work of doctors, pre-classification work needs to be issued. In this paper, a novel and related liver microscopic image classification analysis method is proposed. Objective For quantitative analysis, segmentation is carried out to extract the quantitative information of special organisms in the image for further diagnosis, lesion localization, learning and treating anatomical abnormalities and computer-guided surgery. Methods in the current work, entropy based features of microscopic fibrosis mice’ liver images were analyzed using fuzzy c-cluster, k-means and watershed algorithms based on distance transformations and gradient. A morphological segmentation based on a local threshold was deployed to determine the fibrosis areas of images. Results the segmented target region using the proposed method achieved high effective microscopy fibrosis images segmenting of mice liver in terms of the running time, dice ratio and precision. The image classification experiments were conducted using Gray Level Co-occurrence Matrix (GLCM). The best classification model derived from the established characteristics was GLCM which performed the highest accuracy of classification using a developed Support Vector Machine (SVM). The training model using 11 features was found to be as accurate when only trained by 8 GLCMs. Conclusion The research illustrated the proposed method is a new feasible research approach for microscopy mice liver image segmentation and classification using intelligent image analysis techniques. It is also reported that the average computational time of the proposed approach was only 2.335 seconds, which outperformed other segmentation algorithms with 0.8125 dice ratio and 0.5253 precision
Photoelectrochemical study on the complex of PASP and tungstate as inhibitors of cupronickel B10's corrosion
Photoelectrochemical and AC impedance measurements were conducted to study the effects of environment-friendly inhibitors poly-aspartate(PASP), Na2WO4 and their complex on the corrosion of cupronickel B10 in a borax-buffer solution. The photoelectrochemical measurement results indicated that PASP or Na2WO4 increased the p-type photocurrent which came from the Cu2O layer on the B10 surface. It showed that the inhibitors increased the thickness of the Cu2O layer and decreased the corrosion speed. The optimal concentrations of PASP and Na2WO4 was 3 and 5 mg.L-1, respectively. Na2WO4 increased photocurrent more than mono PASP did. Combined use of PASP and Na2WO4 in a total concentration of 5 mg.L-1, when the mass ratio(PASP: Na2WO4) was 1:1 or 1:3, increased the photocurrent more than their individual use did. The bigger the photocurrent was, the better the inhibition efficiency was. When the mass ratio (PASP: Na2WO4) was 3:1, the combined use increased photocurrent less than their individual use did, the inhibition effect decreased. AC impedance measurement results were well agreed to the photoelectrochemical results
Inhibition action of the self-assembled monolayers of 3-amino-1,2,4-triazole on brass
The anticorrosion and inhibiting mechanism for the self-assembled monolayers (SAMs) of 3-amino-1,2,4-triazole (ATA) on the surface of brass had been investigated by electrochemical method, as well as its adsorption behavior. The results indicated that ATA was liable to interact with brass forming SAMs on the surface of brass. The SAMs changed the structure of the electric-double layer. The SAMs restrained the process of anodic oxidation and had well anticorrosion effect. It was in good agreement with the results by EIS and polarization curve methods. The results from electrochemical measurements indicated that the corrosion resistance for brass electrode was improved by the ATA SAMs. Adsorption of the ATA SAMs was found to follow the Langmuir's adsorption isotherm, and the adsorption mechanism was typical chemisorption
Neutrino Physics with JUNO
The Jiangmen Underground Neutrino Observatory (JUNO), a 20 kton multi-purposeunderground liquid scintillator detector, was proposed with the determinationof the neutrino mass hierarchy as a primary physics goal. It is also capable ofobserving neutrinos from terrestrial and extra-terrestrial sources, includingsupernova burst neutrinos, diffuse supernova neutrino background, geoneutrinos,atmospheric neutrinos, solar neutrinos, as well as exotic searches such asnucleon decays, dark matter, sterile neutrinos, etc. We present the physicsmotivations and the anticipated performance of the JUNO detector for variousproposed measurements. By detecting reactor antineutrinos from two power plantsat 53-km distance, JUNO will determine the neutrino mass hierarchy at a 3-4sigma significance with six years of running. The measurement of antineutrinospectrum will also lead to the precise determination of three out of the sixoscillation parameters to an accuracy of better than 1\%. Neutrino burst from atypical core-collapse supernova at 10 kpc would lead to ~5000inverse-beta-decay events and ~2000 all-flavor neutrino-proton elasticscattering events in JUNO. Detection of DSNB would provide valuable informationon the cosmic star-formation rate and the average core-collapsed neutrinoenergy spectrum. Geo-neutrinos can be detected in JUNO with a rate of ~400events per year, significantly improving the statistics of existing geoneutrinosamples. The JUNO detector is sensitive to several exotic searches, e.g. protondecay via the decay channel. The JUNO detector will providea unique facility to address many outstanding crucial questions in particle andastrophysics. It holds the great potential for further advancing our quest tounderstanding the fundamental properties of neutrinos, one of the buildingblocks of our Universe
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